I'm amused by the contrast between Apple's attention to detail on the implementation and their failure to recognize that a virtual knob with a touchscreen or mouse is a fundamentally bad idea.
The author also makes this error, praising Apple's design prowess and denigrating its competition while failing to recognize they "didn’t always react the way I thought they would" because they're ill-suited to the medium.
It's not all about the interaction, but also the visual representation which can be much finer and granular in small spaces with a knob.
I can make a 16x16px knob where you can see almost the entire 320° of the range.
It's also easier to see fractions, such as 1/2, 1/3 or 1/4.
Sliders, especially in 16px possess none of those.
I was able to debug and fix someone's MainStage patch last night over SMS when they sent me pictures of their screen, where all the knobs were visible.
Being able to see the full state of the thing is important. Hiding it behind interactions is just as bad as hiding it behind menus.
Sidenote, you have to do this on native because pointer lock/warp is not universally supported in web browsers.
As someone who regularly uses DAWs, this sounds like terrible UX
was going to say, heaven forbid we use a little skeumorphism
author here - I made this comment elsewhere, but I still think apple made the right call even if it leads to a bit of confusion at first.
As others have pointed out, sliders have limits & knobs don't, so I do think they have their place on touchscreens.
If a digital knob needs to be turned several times (e.g. 1080º, common in DAWs), the "default" way to interact with a knob on a touchscreen - circling again and again - is slow and uncomfortable. Adding "slider" gestures on top of the default behavior is a nice way to perform many turns quickly and easily.
I'm curious - what UI mechanism would you use instead?
Literally every DAW has knobs everywhere: it would be impossible to use sliders everywhere in a DAW's UI, there simply isn't enough room.